Free Email Deliverability API - Check SPF, DKIM, and DMARC Instantly
October 31, 2025 • InboxGreenEmail Team
🚨 DKIM issues can silently kill replies.
If opens dropped, replies disappeared, or bounces increased, treat it as an incident. Run the scan and get a fix path.
No signup required. Works on any domain.
Meet the InboxGreen Free Email Deliverability API. One GET call returns MX, SPF, and DMARC for any domain - CORS enabled, rate limited, and production safe. Perfect for health checks, dashboards, and CI scripts.
Endpoint
GET https://inboxgreen.email/api/check?domain=example.com
Sample response
{
"status": "ok",
"domain": "example.com",
"timestamp": "2025-10-31T10:10:00Z",
"checks": {
"mx": { "ok": true, "records": [ { "host": "aspmx.l.google.com", "priority": 1 } ] },
"spf": { "ok": true, "record": "v=spf1 include:_spf.google.com ~all" },
"dmarc": { "ok": false, "record": null }
}
}
Quick start
cURL
curl "https://inboxgreen.email/api/check?domain=gmail.com"
JavaScript (browser)
<script>
fetch('https://inboxgreen.email/api/check?domain=gmail.com')
.then(r => r.json())
.then(d => console.log(d));
</script>
PHP
<?php
$json = file_get_contents("https://inboxgreen.email/api/check?domain=gmail.com");
$data = json_decode($json, true);
if (($data['checks']['dmarc']['ok'] ?? false) === false) {
echo "DMARC missing";
} else {
echo $data['checks']['dmarc']['record'];
}
Why this matters
- MX: confirms receiving servers are set
- SPF: lists allowed senders
- DMARC: protects your brand and inbox placement
Limits & keys
Free access with modest per IP rate limiting. For bulk/commercial use or deeper checks (DKIM selectors, headers, scoring), contact us. We’ll offer a paid /api/fullcheck soon with advanced diagnostics and quotas.
Want a full, human friendly diagnosis? Run the Free Checker
Free Deliverability Scan
Check SPF, DKIM, DMARC and List-Unsubscribe for your domain in seconds.